drm/radeon: add support for 3d perf states on older asics

Certain older rv770 asics have both a performance and
a 3D performance state rather than just multiple performance
levels in the state power state.  The current code would
select the performance state rather than the 3D performance
state when the "performance" profile was selected.  This change
switches to the "balanced" profile by default which ends up being
the internal performance profile.  When the user selects the
"performance" profile, it selects the internal 3D performance
state so the user can select the higher performance modes.

For most asics this changes nothing.  For certain rv770 asics
with static performance and 3D performance states, this allows
you to select between then using by selecting the "balanced"
and "performance" dpm profiles.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>